a housing part having at least one receiving opening for the insertion of a pipeline;

a clamping ring arranged in the receiving opening in order to lock the pipeline in place within the receiving opening;

wherein an outer cone surface of the clamping ring interacts with an inner cone surface of the housing part;

the housing part being made in two parts from a base part and an insert part, the insert part being connected to the base part via a snap-action form-fitting connection;

wherein the insert part includes the inner cone surface;

the insert part having a dirt seal for resting on the circumference of the pipeline in place within the receiving opening;

the insert part being of a first, relatively hard and dimensionally stable plastic material;

the dirt seal being of a second relatively soft and elastic plastic material;

the second material being attached directly onto the first material to form a single piece with a material joint therebetween;

wherein retaining edges are formed on the insert part following the inner cone as an axial end stop for the clamping ring;

the insert part including at least two spring arms;

wherein first retaining edges are located near the at least two spring arms;

second retaining edges being situated between the at least two spring arms; and

wherein the first retaining edges are offset with respect to the second retaining edges by an axial offset in the direction of the inner cone whereby the clamping ring, when subjected to a force acting in the pulling-out direction of the pipeline, comes to bear against the first retaining edges, and the at least two spring arms are subjected to a radially outwardly acting retaining-force component.